Ultrasonic machining also known as ultrasonic vibration machining, is a manufacturing process that removes material from a workpiece by combining particles and high-frequency vibrations. Over time, this technique is use to remove material from the workpiece by producing a large number of tiny vibrations.
Fine abrasive particles are applied to the material’s surface during the entire process. Well, in this reading, we’ll explore what ultrasonic machining is, its applications, parts, diagrams, types, and how it works. The advantages and disadvantages of ultrasonic machining will also be discussed.
Let’s get started!
What is Ultrasonic Machining?
Ultrasonic machining is an unconventional manufacturing technique that uses small abrasive particles and high-frequency, low-amplitude tool vibrations on a material surface. This technique reduces brittle fracture during hammering by using a ductile tool material, which makes it easier to remove material precisely and machine delicate components.
The tool moves vertically or orthogonally to the part’s surface at amplitudes ranging from 0.05 to 0.125 mm (0.002 to 0.005 in.). A fine mixture of abrasive grains and water creates a slurry, which is then applied to both the part and the tooltip. Grain sizes typically range from 100 to 1000, with smaller grains resulting in smoother surface finishes. Ultrasonic vibration machining is commonly employed for brittle and high-hardness materials because of the mechanics of microcracking.
In addition, the tool generates vibrations that propel micro-sized particles towards the workpiece, which are combined with water or other liquids to form a slurry. Upon activation, these particles are propelled rapidly toward the surface of the workpiece, enabling their abrasive properties to effectively remove material.
Applications
Ultrasonic machining is an advanced machining technique that specializes in processing non-conductive ceramics and produces ceramic components with precise form and intricate patterns. It ensures precise results and little material loss while machining sensitive materials. The technique offers accuracy and consistency in die manufacturing and is used to create dies for wire drawing, punching, and blanking operations.
It enables dental professionals to make holes of different forms painlessly, guaranteeing an accurate and cozy treatment. Ultrasonic Machining is employed for the precise grinding of materials such as quartz, glass, and ceramics, offering superior surface finishes and dimensional precision.
It helps to cut industrial diamonds, accomplishing exact and complicated cuts in expensive and resilient materials. Die fabrication is also an application of ultrasonic machining, including the production of molds for casting, embossing, and forming processes. This accuracy is used in the fabrication of micro-electro-mechanical system components, including micro-structured glass wafers, where diamonds are shaped to specific forms.
Related: What is NC Machining? it Types and How it Works
Parts of an Ultrasonic Machining
The power source, velocity transformer, tool, abrasive slurry, electro-mechanical transducer, abrasive slurry and workpiece itself make up the several tools used in ultrasonic machining.
A power supply transforms electrical supply into a high-frequency electrical supply with tiny vibration amplitudes, usually between 20 and 40 kHz. The transducer’s vibration is enhanced and focused by the velocity transformer, which makes it appropriate for powering the tool during cutting.
To remove material from the workpiece, abrasive particles are used to strike or percussion the ductile tool. Because ultrasonic frequencies accelerate the hammering pace, tool wear and fatigue resistance are essential. For effective machining, a slurry of abrasive particles is placed between the tool and the workpiece, and new abrasives are continually delivered by a water jet.
An essential component of a machine is the workpiece, where an electro-mechanical transducer ensures control and accuracy by converting electrical energy into mechanical vibrations.
The cannon guarantees a steady supply of new abrasives at controlled pressure by delivering abrasive slurry through a water medium. This method is perfect for precisely cutting complex 3D structures out of brittle, non-conductive materials like cramics.
Diagram
Types of Ultrasonic Machining
The common types of ultrasonic machining are rotary ultrasonic vibration machining and chemical-assisted ultrasonic vibration machining.
Rotary Ultrasonic Machining
Rotary ultrasonic vibration machining (RUM) serves an innovative manufacturing process used for the machining of advanced materials, including ceramics and alloys such as glass, quartz, structural ceramics, titanium alloys, alumina, and silicon carbide. The tool’s surface is embedded with diamonds, enabling the precise grinding of the part.
Researchers are actively engaged in improving the process at the micro-level, enabling the machine to function in a similar way to a milling machine, which will improve the precision of the machining process.
Chemical-Assisted Ultrasonic Machining
Chemical-assisted ultrasonic machining (CUSM) improves surface quality and increases the material removal rate for glass and ceramic materials when compared to conventional techniques. The application of an acidic solution such as hydrofluoric acid enhances machining characteristics.
The entrance profile diameter may exhibit a slight increase as a result of the enhanced chemical reactivity associated with the new slurry selection. It is essential to carefully choose the acid content to maintain user safety and ensure product quality.
How Does Ultrasonic Machining Works?
A slurry of abrasive particles is placed between a ductile tool and the workpiece, creating a 0.25 mm gap in the process of ultrasonic machining. With a slightly tapered tool, the slurry efficiently removes material, allowing for material scrubbing and straight holes. The frequency of the vibrating tool, the size of the abrasive slurry grains, the stiffness, and the viscosity all affect how long a person stays on the ultrasonic machine.
Numerous factors, such as the carrier fluid’s viscosity, frequency, amplitude, and the size and concentration of the abrasives, influence the material removal rate (MRR) in ultrasonic machining. Additional impacts from higher abrasive concentrations raise MRR until momentum loss happens, which lowers MRR. Likewise, bigger abrasive sizes provide bigger impact areas, but going above a specific size reduces the abrasives’ speed.
Ultrasonic Machining is ranked between Electrochemical Machining (ECM) and Electrical Discharge Machining (EDM) in terms of material removal rate.
Related: What is Electrochemical Grinding (ECG)? Its Parts & How it Works
Advantages and Disadvantages of Ultrasonic Machining
A flexible and effective technique for precisely shaping and removing material from delicate materials is ultrasonic machining. It is appropriate for non-metallic materials with low electrical conductivity because of its low heat generation and compatibility with other technologies such as EDM, ECG, and ECM.
Clean and accurate surfaces are produced with ultrasonic machining, which eliminates burrs and distortion. For increased functionality and adaptability in material removal processes, it can be combined with other cutting-edge technologies. Because ultrasonic machining produces no noise, it may be used in environments with low noise levels.
Both experienced and novice workers can operate the equipment with ease thanks to its user-friendly design. The procedure ensures the manufacturing of accurate and delicately formed components by providing high precision and good surface finish.
Its drawbacks, however, include a limited rate of material removal, a high energy require, and challenges when it comes to machining delicate materials. The strong impact of abrasive particles can cause deformation and damage to these materials.
Furthermore, limited slurry flow might make deep hole drilling difficult and could impede efficient material removal. Additionally, the slurry’s abrasive particles shorten tool life and increase tool wear, requiring frequent tool replacements.